ADHD Prevalence Still Rising, CDC Says

Rates of parent-reported diagnoses of attention deficit-hyperactivity disorder (ADHD) continued their upward trend through 2011, government researchers said.

by John Gever John Gever Deputy Managing Editor, MedPage Today
November 25, 2013

Action Points

Note that this telephone survey of American households suggests that the prevalence of ADHD has risen from 2007 to 2011.

Be aware that the inclusion of cell-phone-only households in 2011 may have increased the measured prevalence.

Rates of parent-reported diagnoses of attention deficit-hyperactivity disorder (ADHD) continued their upward trend through 2011, government researchers said.

Data from the 2011 edition of the National Survey of Children's Health (NSCH) indicated that 11% (95% CI 1.5%-11.5%) of children 4 to 17 years of age had at one time or another received a diagnosis of ADHD, up from 9.5% in the 2007 NSCH results, according to Susanna N. Visser, MS, of the CDC in Atlanta, and colleagues.

The 2011 numbers were reported by parents of more than 76,000 American children responding to the survey.

The earlier report from the same group, based on 2007 NSCH results with a similar methodology, indicated a rate of current ADHD diagnosis of 7.2% (95% CI 6.8%-7.7%), and of current diagnosis and medication of 4.8% (95% CI 4.4%-5.1%).

Visser and colleagues acknowledged that, although parental reports do not necessarily reflect accurate guideline-compatible diagnoses of ADHD, the rising totals do have important implications.

"Parent-reported prevalence estimates provide insight into the demand that this population has on the systems supporting them," the researchers observed.

Also, to the extent that medication use really is rising as much as these data indicate, the findings reinforce the need for more research on its effects, Visser and colleagues suggested.

"We do not fully understand the long-term impact of taking ADHD medication over time," they wrote. "However, there is also some evidence that long-term use of ADHD medication normalizes right dorsolateral prefrontal cortex activation ... . Given the increasing medication treatment patterns and the developing literature about the risks of both intervening and failing to intervene, continued research on the long-term benefits of ADHD treatment, both pharmacological and behavioral, is needed."

In an accompanying editorial, John Walkup, MD, and two colleagues at Weill Cornell Medical College in New York City said the finding that about 30% of children reported to have ADHD are not taking medications is a cause for concern.

"Although not every child or adolescent with ADHD requires medication treatment, the study documents a pattern of undertreatment," they wrote.

This, they added, "is an important take-home message from this study." They went on to argue that the apparently rising rates of diagnosis should not be interpreted as overdiagnosis and overtreatment. Rather, "the CDC data suggest that we are getting to a point when children with ADHD in the U. S. may actually be getting an opportunity for a diagnostic assessment and appropriate evidence-based treatment."

The NCHS is a telephone survey that, in 2011, included cell-phone numbers as well as landlines. A total of nearly 96,000 interviews were conducted with primary adult caregivers of children, mostly parents. The ADHD questions were part of a supplement and were asked about a randomly selected child of any age 17 or younger in the household.

The lifetime prevalence question was "Has a doctor or other healthcare provider ever told you that [child] had attention deficit disorder or attention deficit-hyperactivity disorder, that is, ADD or ADHD?" Respondents were also asked whether the child currently had such a diagnosis and at what age the diagnosis was made.

In addition, for children with a current diagnosis, respondents graded the severity and were asked whether the child was taking an ADHD-specific medication.

Results indicated that parent-reported ADHD is much less prevalent among children of Hispanic and Asian ancestry and among those in non-English speaking households. The lifetime prevalence for respondents not classed as white or black was 7.2% (95% CI 6.3%-8.1%); it was 2.7% (95% CI 1.9%-3.7%) in households where the primary language was not English.

Prevalence was also associated inversely with household income. In households with income below the federal poverty line, lifetime prevalence was 12.9%, compared with 10.0% in households with income above twice the poverty level. Similarly, the rate in households using Medicaid/SCHIP insurance was 14.4% (95% CI 13.5%-15.4%) compared with 9.4% (95% CI 8.9%-10.0%) in households with private insurance.

Rates were lower as well among households in western states compared with those elsewhere (8.1% versus 10.% to 12.6% in the Northeast, Midwest, and South).

These patterns were also reflected in data on current ADHD diagnoses and the use of ADHD medications.

In addition to the study's reliance on parental reports for ADHD diagnoses, Visser and colleagues noted that the inclusion of cell-phone numbers in the 2011 survey might have overestimated the change in prevalence from earlier surveys.

Earlier surveys included only landlines, they explained. In the 2011 results, current ADHD diagnoses were substantially more prevalent in cell phone-only households (10.0% versus 8.4% in landline households). Consequently, they concluded that ADHD prevalence may have been underestimated in 2007 and earlier.

The CDC funded the work. All authors were government employees and reported that they had no financial conflicts of interest.

Walkup reported relationships with Shire, Pfizer, Lilly, Abbott, and two medical publishers. Other editorial authors declared they had no relevant financial interests.

Reviewed by F. Perry Wilson, MD, MSCE Instructor of Medicine, Perelman School of Medicine at the University of Pennsylvania and Dorothy Caputo, MA, BSN, RN, Nurse Planner

MedPageToday is a trusted and reliable source for clinical and policy coverage that directly affects the lives and practices of health care professionals.

Physicians and other healthcare professionals may also receive Continuing Medical Education (CME) and Continuing Education (CE) credits at no cost for participating in MedPage Today-hosted educational activities.